matrix-nginx-proxy: adding additional configuration blocks

roles/matrix-nginx-proxy/templates/nginx/conf.d/nginx-http.conf.j2

@@ -3,4 +3,7 @@
 # which can sometimes be too low to handle our 2 vhosts (Synapse and Riot).
 #
 # Thus, we ensure a larger bucket size value is used.
-server_names_hash_bucket_size 64;
+server_names_hash_bucket_size 64;
+{% for configuration_block in matrix_nginx_proxy_proxy_http_additional_server_configuration_blocks %}
+	{{- configuration_block }}
+{% endfor %}